The invention relates to a mounting device for roller blinds comprising a terminating plug for a roller blind tube, said plug having an oblong hole for interaction with a spade-shaped element on a mounting bracket, in which at least one longer side of the hole being shaped as a plane surface parallel to the axis at a distance from said axis corresponding to half the thickness of the spade-shaped element, and that there is provided a lock, which is constituted of the inside of a slit circular ring, rotatable to locking around said spade-shaped element upon mounting.
Several conditions have to be fulfilled when mounting roller blinds with a built-in spring. One end must be prevented from rotating, and the roller blind mounting bracket must be fitted as closely as possible to the upper delimitation of a niche or cassette. Traditionally the rotation is prevented by means of a spade-shaped element, which projects axially into or out of the roller blind tube, interacting with a hole that surrounds the flat element in a suitable manner. In another type of roller blinds having exterior winding and unwinding both ends have to rotate. This is in practice obtained by using spade-shaped elements in both brackets, which may be identical, and the rotation is assured by means of a bearing built into the terminating plugs fitted to the roller blind tube. The length of the roller bearing tube should correspond to the width of the niche, and hence the mounting is traditionally performed by mounting one end of the tube in one of the brackets, whereupon a projecting spade-shaped element is pushed horizontally into a slit in the other bracket, whereupon it is swung down to be supported and held in the centre of the bracket. The force of gravity ensures that this end remains in the bracket. Conditions are not the same, if the spade-shaped element is carried by the bracket and has to interact with a hole in one end of the roller blind tube. In this situation it is necessary that both ends are fitted with brackets, and that one of them is subsequently fixed by screws. It is a complicated mounting, which is unsuitable if corrections have to be performed on the roller blind, that may necessitate its removal once again.
Known mounting brackets may have a horizontal as well as a vertical spade-shaped element. It is not possible to transfer the slit in the bracket to one of the roller blind, because this slit would not have a suitable orientation, whereby a sideways pull in the roller blind would be able to pull it loose. In case space were made available in the end of the roller blind for a construction so that the roller blind were retained by means of the force of gravity, it must then be lifted so much with respect to the bracket, that both brackets have to be lowered during mounting (to preserve the horizontal axis of the roller blind), and hence the roller blind is not fitted as closely as possible to the upper delimitation as possible. Furthermore it would not be possible to use a mounting bracket having a vertical spade-shaped element.